On a method of estimating the multiaxial low-cycle fatigue life nonproportional loading conditions

摘要

We present a method of estimating the multiaxial low-cycle fatigue life under nonproportional loading, which is based on the equivalent strain concept. An equivalent strain range is a function of a single argument - the strain path, with a material constant related to the additional hardening of the material under nonproportional loading conditions. We propose a new material parameter that is universally applicable to the materials with small and large additional hardening. This approach is based on the plastic strain work per cycle. The proposed material parameter gives a good correlation with durability of stainless steel 08Kh18N10T and titanium alloy VT9 under nonproportional low-cycle loading conditions.